body {
	/* % 一般是根据父元素的宽高计算，如果父元素没有设置宽高，则跟随浏览器窗口大小计算 */
	width: 100%;
	height: 100vh;
	/* 重复线性渐变背景图像 */
	background-image: repeating-linear-gradient(45deg, #99000040 0, #99000040 10px, #ffcc0040 10px, #ffcc0040 20px);
	background-color: white;
	/* 图层混合模式 同 PS */
	background-blend-mode: luminosity;
}
.menu{
	display: flex;
	justify-content: center;
	padding-top: 16px;
	margin-bottom: 16px;
}
.file_inp {
    position: relative;
    display: inline-block;
    background: #D0EEFF;
    border: 1px solid #99D3F5;
    border-radius: 4px;
    padding: 4px 12px;
    overflow: hidden;
    color: #1E88C7;
    text-decoration: none;
    text-indent: 0;
    line-height: 20px;
}

.file_inp input {
    position: absolute;
	width: 100%;
	font-size: 20px;
    right: 0;
    top: 0;
    opacity: 0;
}
.rand_btn{
	font-size: 16px;
	padding: 0;
	line-height: 16px;
	color: #1E88C7;
	border: 0;
	background: transparent;
}
.rand_btn:hover,
.file_inp:hover {
    background: #AADFFD;
    border-color: #78C3F3;
    color: #004974;
    text-decoration: none;
}

.pic_container {
	display: flex;
	flex-wrap: wrap;
	width: 300px;
	height: 300px;
	margin: 0 auto;
}

.select {
	border-color: red !important;
}

.bg{
	width: 100px;
	height: 100px;
	/* 使用平铺径向渐变 */
	background-image: repeating-radial-gradient(circle,red 20px,orange 30px,yellow 40px,red 50px);
}